Month: December 2022

Marsh grass shrimp (Palaemonetes vulgaris) are impressively fast and nimble swimmers, as anyone who's seen them zipping about tide pools at the beach can attest. Nils Tack, a postdoctoral researcher at Brown University, studies the biomechanics and fluid dynamics of how these little creatures manage the feat. He presented his latest findings at a recent American Physical Society meeting on fluid dynamics in Indianapolis. Essentially, the shrimp uses its flexible and closely spaced legs to reduce drag significantly. The findings will help scientists design more efficient bio-inspired robots for exploring and monitoring underwater environments.

Tack is a biologist by training, currently working in the lab of Monica Wilhelmus. Earlier this year, the group introduced RoboKrill, a small one-legged 3D-printed robot designed to mimic the leg movement of krill (Euphasia superba) so it can move smoothly in underwater environments. Granted, the robot is significantly larger than actual krill—about 10 times larger, in fact. But it's challenging to keep and study krill in the lab. RoboKrill's "leg" copied the structure of the krill's swimmerets with a pair of gear-powered appendages, and Wilhelmus et al. used high-speed imaging to measure the angle of its appendages as it moved through water. Not only did RoboKrill produce similar patterns to real krill, but it could mimic the swimming dynamics of other organisms by adjusting the appendages. They hope to one day use the robot to monitor krill swarms in the wild.

Regarding the marsh grass shrimp's swimming style, prior studies showed that the creatures could maximize forward thrust thanks to the stiffness and increased surface area of its legs. That research essentially treated the legs (aka pleopods) as paddles or flat plates pushing on water. But nobody looked closely at how the legs bent during recovery strokes. "It's a very complex system," said Tack during a briefing at the meeting. "We try to approach [the topic] through two angles, looking at the fluid and looking at the mechanical properties of the legs."

Enlarge / An AI-generated illustration of an AI-hallucinated computer. (credit: Benj Edwards / Ars Technica)

Over the weekend, experimenters discovered that OpenAI's new chatbot, ChatGPT, can hallucinate simulations of Linux shells and imagine dialing into a bulletin board system (BBS). The chatbot, based on a deep learning AI model, uses its stored knowledge to simulate Linux with surprising results, including executing Python code and browsing virtual websites.

Last week, OpenAI made ChatGPT freely available during a testing phase, which has led to people probing its capabilities and weaknesses in novel ways.

On Saturday, a DeepMind research scientist named Jonas Degrave worked out how to instruct ChatGPT to act like a Linux shell by entering this prompt:

Enlarge / Vials of the Pfizer COVID-19 vaccine. (credit: SOPA images)

With respiratory illnesses ravaging children around the US, vaccine partners Pfizer and BioNTech announced Monday that they are seeking regulatory authorization to offer their bivalent COVID-19 vaccine to children ages 6 months to 4 years—but not as a booster; instead it would be part of an updated primary series.

Currently, the bivalent vaccine, which targets the coronavirus omicron subvariants BA.4 and BA.5 in addition to an ancestral strain, is only available as a booster dose to Americans ages 5 years and up. Although BA.5 is no longer dominant in the US, its sublineages now reign. The Centers for Disease Control and Prevention recently published real-world effectiveness data indicating that the bivalent boosters increased protection against symptomatic COVID-19 infection over protection provided by the previous boosters.

For now, children under 5 only have had access to a primary series—two small doses of Moderna's original vaccine or three small doses of Pfizer/BioNTech's original vaccine. Both were first authorized on June 17 after a rollercoaster regulatory process that lasted months.

Enlarge / If you're going to come at port 443, you best not miss (or forget to put a space between URL and port). (credit: Getty Images)

KmsdBot, a cryptomining botnet that could also be used for denial-of-service (DDOS) attacks, broke into systems through weak secure shell credentials. It could remotely control a system, it was hard to reverse-engineer, didn't stay persistent, and could target multiple architectures. KmsdBot was a complex malware with no easy fix.

That was the case until researchers at Akamai Security Research witnessed a novel solution: forgetting to put a space between an IP address and a port in a command. And it came from whoever was controlling the botnet.

With no error-checking built in, sending KmsdBot a malformed command—like its controllers did one day while Akamai was watching—created a panic crash with an "index out of range" error. Because there's no persistence, the bot stays down, and malicious agents would need to reinfect a machine and rebuild the bot's functions. It is, as Akamai notes, "a nice story" and "a strong example of the fickle nature of technology."

Enlarge / An intensive care nurse cares for a patient suffering from respiratory syncytial virus (RSV), who is being ventilated in the children's intensive care unit of the Olga Hospital of the Stuttgart Clinic in Germany. (credit: Getty | picture alliance)

With SARS-CoV-2 still circulating and seasonal viruses, including influenza and RSV, making up for lost time during the pandemic, the US is getting slammed by respiratory illnesses. And things could get worse as more holidays and associated gatherings approach, health officials warned Monday.

"This year's flu season is off to a rough start. Flu's here, it started early and with COVID and RSV also circulating, it's a perfect storm for a terrible holiday season," Sandra Fryhofer, chair of the American Medical Association and adjunct medicine professor at Emory University School of Medicine, said in a press briefing held by the Centers for Disease Control and Prevention today. "Over the last few years, COVID-protective measures also prevented spread of flu and other respiratory infections, but we're really no longer in that bubble."

Cases of influenza-like illnesses (ILIs) are soaring throughout the country, with 47 states seeing "very high" or "high" activity levels, according to the latest CDC data. The agency estimates that there have been at least 8.7 million illnesses, 78,000 hospitalizations, and 4,500 deaths from flu.

Enlarge (credit: Aurich Lawson)

In January, Colorado police officers confined a 77-year-old grandmother named Ruby Johnson for hours in a squad car without even offering a glass of water during a time when she was due to take her daily medications—why?

Nobody told Johnson what was going on when she opened her front door to a SWAT team assembled on her lawn. Much later, she found out about a stolen truck—reportedly with six guns and an iPhone stashed inside—wrongly believed to be parked in her garage based on no evidence other than her home being located within a wide blue circle drawn by a “Find My” iPhone app. Now she’s suing a Denver cop for conducting what she believes was an illegal search of her home based on what her legal team describes as either an intentionally or recklessly defective application for a search warrant that was “wholly devoid of probable cause.” Because of the allegedly improper raid, the retired US Postal Service worker had to “endure an unreasonable search and seizure, unlawful police confinement, and severe physical and emotional distress.”

“This illegal search has destroyed Ms. Johnson’s sense of safety and security in the home that has been her castle for 40 years,” Johnson’s complaint reads.